package me.yobol.blog.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;

@WebFilter(filterName="EncodingFilter",
		   urlPatterns={"/*"},
		   initParams={
				@WebInitParam(name="encoding",value="UTF-8")
		   })
public class EncodingFilter implements Filter{

	private String characterEncoding = null;
	
	@Override
	public void init(FilterConfig config) throws ServletException {
		characterEncoding = config.getInitParameter("encoding");
		if(characterEncoding == null){
			throw new ServletException("Encoding is not specified.");
		}
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		if(!characterEncoding.equals(request.getCharacterEncoding())){
			request.setCharacterEncoding(characterEncoding);
		}
		response.setCharacterEncoding(characterEncoding);
		chain.doFilter(request, response);
	}
	
	@Override
	public void destroy() {
		
	}

}
